I have a wireless NIC (wifi network card) in my laptop that can't receive signals too well. I'm lucky I can get internet on it at home (West Hamilton). As soon as I hit Downtown, I get a couple of network names, but I am not able to connect to any of them. This is even with the internal laptop antenna's connected to the "Main" connector of the NIC.

I read up on the internet that external amplifiers connected to the card have made improvements to several people's connections.

I want to make my own amplifier and hook it up to my laptop antenna. I can make amplifiers in general, and even the worst amplifier can do something, even if it means boosting the signal by 1%.

So I was wondering, in a typical wifi card, is one pin of the antenna port the actual antenna that is shared simultaneously between both the transmitter and the receiver, and the other pin the ground?

I need to know how the "main" port works on a wifi card before I can continue.

Instead of trying to build a booster, make a corner reflector. It'll take you under a half-hour using materials you already have, among many other benefits (like not voiding your warranty.) Depending upon how accurately you make and position it, you can get up to a 10dB increase in your signal (directionally, of course.)